1. Field of the Invention
The present invention relates to a display device and a power control device.
2. Description of the Prior Art
As the information society develops, display devices for displaying an image are being increasingly required in various forms, and in recent years, various display devices such as Liquid Crystal Displays (LCDs), Plasma Display Panels (PDPs), and Organic Light Emitting Display Devices (OLEDs) have been utilized.
The display device includes a display panel, a data drive unit and a gate drive unit. The display panel includes data lines and gate lines, and sub-pixels are defined at each point where the data lines and the gate lines intersect. The display device further includes a data drive unit which provides data signals to the data lines and a gate drive unit which provides scan signals to the gate lines.
A transistor is disposed at each sub-pixel defined in the display panel, and a unique characteristic value such as the threshold voltage, mobility, or the like of the transistor in each sub-pixel may change according to the drive time or the unique characteristic value deviation of the transistor between sub-pixels may occur. In another case, when the display device is an organic light emitting display device, the deviation of the degradation of the organic Light Emitting Diode (OLED) in each sub-pixel may occur. This phenomenon may generate a luminance deviation between each of the sub-pixels, thereby decreasing image quality.
Thus, in order to compensate for a luminance deviation between each of the sub-pixels, a compensation technique is proposed for compensating for the changes or deviations of the characteristic values of the circuit elements (e.g., transistors, organic light emitting diodes).
This sub-pixel luminance deviation compensation senses a voltage at a particular node of a circuit in the sub-pixel, converts the sensed voltage to a digital value and generates sensing data, and then calculates the data compensation amount of data to be supplied to each sub-pixel based on the generated sensing data, and changes the data according to the compensation amount of the calculated data and then supplies the changed data to each sub-pixel, thereby performing sub-pixel luminance deviation compensation.
However, sub-pixel luminance deviation compensation causes an unexpected decrease in image quality, such as by creating a block dim phenomenon along the vertical direction.